Mixing bass drums.

Ever wonder how come some of the mixes you’ve heard sound really punchy and phat? More often than not, what you’ve heard was the result of mastering.

But, were these great sounding bass drums the result of the mastering process alone? The answer is No. The mix itself has to have the correct bass drum level, eq and compression for this great sound to emerge.

It all starts with what you choose as your main bass drum.

Did I say the main?

Yes, you may not be even aware that the reason some bass drums sound 'huge' is because of the layering of multiple kick drums (multi-layer kick drums).

The best dance remixers in the world will tell you that in order to get a 'big kick drum' sound, you need to layer two or more bass drums that complement each other. In theory, if you doubled the same sound, you only increase magnitude so you end up with the same thing, only louder. That's not what we are after. If you shift the other drum, the result is a phasey kick drum. We don't want that either. 

You need to understand what is needed for your bottom end in the first place. For example, there are thin kick drums that have great punch and there are heavy boomy kick drums that have a 'phat' sound which gives a tremendous presence (weight) in all lower frequencies, including sub sonic content.

Furthermore, you could have 2 different types of bass drums with similar fundamentals, harmonics and sub harmonics, but with two different beat patterns which create an excitement to the bottom end (i.e. one on the downbeat and the other one off with a slight time shift)

While these tips may not work for some of you who - for instance - record and mix classical, pop, country, blues or even some rock, they are a must do for most dance, reggae, hip hop and even some R&B mixes.

Even when two bass drums are not layered together, you can usually hear a second one, for example, coming from a sample loop.

BTW, if your drum foundation is based on one sampled beat loop, you need to make sure that the sample was well recorded and that all frequencies needed to create a basic and exciting  rhythm track are represented. Because you can't control individual drum levels on sampled beats, the results are usually not professional enough so you end up disappointed when compared to most commercially released tracks.

Going back to kick drum, one thing that remains constant in all music genres, whatever kick drum you choose for your mix, is that it needs to be at the correct level.

This is perhaps more important than any fancy multi-layered kick drum arrangement at the end of the day because if the bass drums are not leveled high up enough in the mix, the purpose of multi-layering them in the first place is defeated .

Compression (See article)

It is through this processor that we can obtain control over bass drum dynamics. There are no set rules of thumb to get the best sound out of a compressor, but its correct use is as important as its frequency equalization (How the kick track gets equalized in respect to the big picture).

Most beginners squash the signal with the wrong amount of threshold, ratio, and kill the punch by not changing the attack time. If you are not sure of what you are doing, just set the threshold so that your gain reduction is about 3 dB. Change your attack to 20ms and start with a soft compression ratio of 2:1, and literally, play it by ear.

For the most part,  it’s always better to leave a bass drum uncompressed with higher dynamics at the correct level than a squashed kick drum {over-compressed} at the wrong level.

There are other tricks like copying the same bass drum to another track and re-arranging or filtering the frequencies between 38Hz and 200Hz, so that the result is a second kick track with more punch but without sub sonic information. Mixed together with the original  bass drum track, it will get the punch that is lacking (more about this on another article :-)  

Equalizing.

This is where lots of you can't get it right most of the time. The reason is the lack of a control room for mixing and your studio monitors. Trust me, unless you are truly working in a professional studio environment or have tons of experience mixing, you’ll never get it right.

That doesn’t mean that you will never get the kick in your mix to sound good enough for the mastering guy to master it. The most frequent mistake is to submit a mix with a weak sounding kick drum and expect the mastering process to “magically” make it sound like that killer-phat bass drum you heard from the last DMX CD, or a slamming dance track from remixer Moby.

Forget it.

The most common mistake is to over-boost the lows with a generic low-frequency shelving filter or bump some of the lows where it wasn't needed with a bell eq and expect that the mastering engineer will make it sound bigger at his end. Again, it's not going to happen. We may try some corrective equalization, but again, if the fundamentals are not there, expect disappointing results.

We (ME’s) have tricks to fix some bass drum issues, but 90% of the time these badly compressed, equalized and mixed kicks come with similar bass-line problems.

The result is a mess in the low end that nobody can fix, except you of course, but at your end.

Mixing kick and bassline

Now, leveling the bass drum is half the story .

Whether it’s a real fender bass guitar or a PCM {pulse code modulation} bass sample, how you layer these two will result in a well defined or undefined bass area. Working with a low cut eq filter  a.k.a. HPF, could be the best tool to separate a kick from a bassline, but careful attention should be paid to their relative levels.

The bassline should be present but never overtaking the bass drum at any given moment throughout the mix. Also, panning the bass drum or the bassline more to one side of the stereo field is impractical because bass sounds have more weight and sound better when they are panned dead center. So, avoid panning these to the side channels.

One technique often used when mixing these two tracks/elements is 'ducking'.

Ducking

Suppose you have a bass and a drum track (both audio not MIDI) but it seems that the kick drum sound gets "blurred" because of the bass, both have to coexist in approximately the same frequency range and the presence of the bassline tends to overwhelm the kick drum's presence. It would then be nice if the bass was a bit softer each time the kick drum hits, right? The solution is known as "ducking" (the bass "ducks" each time the kick hits).

The picture shows the setup described above. Notice that the kick is currently playing (level meter) and the Compressor's "Gain Reduction" meter indeed shows the Compressor to be activated.

On the bass track, insert a Compressor. However, instead of letting the bass sound itself trigger the Compressor (as would normally be the case), you now pick the kick drum track from the Side Chain popup menu in the compressor. (Note that the names of the Audio Objects will not show up in the popup; you have to pick the right object by looking at the Object's parameter pane or on its channel strip, right below its Output pop-up). Additionally (important) you have to switch off "Auto Gain" in the Compressor. What you have now is a bass track that only gets compressed when the kick drum is active, thus creating a kind of "pocket" for the kick to sit inside. As for the Auto Gain: when this is on, Logic will compensate the attenuation that takes place in the Compressor, by amplifying the output signal. In this particular case you explicitly do not want that to happen: the entire idea is centered around getting the bass to play softer. Auto Gain would destroy that.

OK! Finally, try not to have your drums and bass line sub mixed {stem mixing}, if you do or you have to, then be sure to have the ability to go back to the original drum mix session to adjust/correct and sub mix them back to two tracks again. Needless to say that once imported back to your session, your sub mix should be panned one track hard left and the other hard right, if not, the side channels go to the center and you may distort you two-track stereo sub-mix .

Another thing, try not to mix directly from a MIDI drum machine and/or other tone generators (via syncing to SMPTE/MTC or other) if they don't have separate outputs to individual drum instruments. If you do and the bass drum doesn't sound correct, you will need to adjust levels from the parameter menus in those units and try again until you get it right. The draw back of working this way is that usually those MIDI devices don't have any sound reinforcement gear built-in, like compressors and equalizers. What you hear is what you get and there maybe some latency issues with this method as well. So, transfer the sounds {again separately, if possible) to a workstation {DAW} and use your audio software to mix and tweak your tracks there.

As a ME, I have been able to re-build and re-shape bass from badly mixed music sources, but don’t count on this as part of the mastering process. Ultimately, it’s you and not the mastering guy who has to make sure that the sound of the bass drum(s) in your music and the overall mix is good for the mastering stage. You must be happy with the sound of your drums and bass in the first place and prior to order mastering. And don't forget, if the mix doesn't already stand on its own, you need to go back and figure out what you need to change to make sound great.